In the Chicago Tribune, Chris Jones wonders whether 90 minutes is the right length for a show. He says it depends, and I'd have to agree with him.
I've seen some 90 minute musicals, like 13 and A Catered Affair, for example, that I really loved. I spent about 7 1/2 hours watching all three parts of The Norman Conquests and it was bliss. The 3 hours and 15 minutes of August: Osage County flew by.
But I realize that not everyone is me, and attention spans are shorter these days. If people are seeing an evening performance and they have to get to work the next day, they want to get home at a reasonable hour. If I'm at home and not in New York City on vacation, 90 minutes looks more attractive.
The article reminds me of a Working in the Theatre podcast on the marketing of Broadway that I watched recently. The guests, all experienced at designing campaigns to sell plays and musicals, were talking about the success of God of Carnage, a 90-minute play.
Drew Hodges founder and CEO of the theatrical advertising agency SpotCo, said: "I'm sure we've all asked to put 90 minutes no intermission in the ads. ... A really good show that's short is the holy grail."
(On the other hand, can a show be too short? According to Telecharge, the Broadway revival of David Mamet's Oleanna, with Bill Pullman and Julia Stiles, clocks in at 1 hour and 15 minutes, and rear mezzanine tickets are $76.50.)
Personally, I think the playwright or composer has to know how long their work needs to be. Knowing when to stop is one of the hardest things for any writer to learn. I'm certainly guilty of being long-winded on my blog. (Although no one's paying to read it.)
To attract me as an audience member, the key is an absorbing story and compelling characters. Then I'll stay with you for as long as it takes.